Various forms of data encryption may be applied to communications transmitted over a network for the purpose of securing information. The concept of the virtual private network (VPN), for example, typically relies on one or more forms of encryption in combination with a tunneling protocol to prevent or reduce disclosure of private information. Common encryption protocols used for VPNs include IPSec, SSL/TLS, MPPE, and SSTP to name a few examples. In the context of wireless networks such as Wi-Fi, for example, encryption over the air interface may take the form of WEP, WPA (including TKIP), or WPA2 (including CCMP), for example.
Various forms of encryption may be applied in combination and at one or more different levels of a protocol stack for network communications. For example, one form of encryption may be applied to data passing from a first layer that is encapsulated and encrypted using a different form of encryption that is applied at a second layer. Encryption protocols may be further defined as being either a point-to-point (e.g., transport level) encryption protocol or a message level encryption protocol, with each protocol having its own respective advantages and disadvantages.
Wireless devices such as smartphones, tablet computers, laptop computers, etc. have the benefit of being mobile. This mobility enables wireless devices to obtain network connectivity through a variety of different access points using a variety of different wireless protocols. Many wireless devices available today offer support for two, three, or more different wireless protocols. For example, many smartphones support 3G and 4G cellular protocols, Wi-Fi, and Bluetooth.
Additionally, network access points may be owned or operated by a variety of different entities, including publicly available cellular carriers with which a client accessing the network is a subscriber, publicly available cellular carriers with which the client accessing the network is not a subscriber, and private individuals and organizations that operate publicly accessible or private wireless networks. Each of these entities may implement different policies for their wireless networks, including different forms of security and rules for the data traversing their networks.